The plant will remain out of operation until the explosion is investigated and damage is repaired. Reint says it's unclear how long that will take. The plant employs about 50 people and operates 24 hours a day.

A company website says Wichita, Kansas-based Flint Hills Resources bought the plant in September 2013. The plant began operating in 2008 and produces 110 million gallons of ethanol a year.